As used herein, the term “soil” refers to any particulate material of the earth, such as one or more of clay, sand, silt and/or decomposed granite, whether or not it contains organic matter. The term “clay” refers to any (1) inorganic earth surface material that is plastic when moist but hard when fired and that is comprised primarily of hydrous aluminum silicates and other minerals, or (2) substance having the properties of clay. Clay includes dry and wet clay and may or may not include organic matter.
The term “sand” means a loose granular material formed by the disintegration of rocks to form particles smaller than gravel but coarser than silt. Sand may or may not include organic matter. The term “silt” means loose, unconsolidated sedimentary material with rock particles usually 1/20 millimeter or less in diameter, and being generally smaller than sand but coarser than clay. Silt may or may not include organic matter.
As used herein, the term “decomposed granite” means granite rock decomposed into smaller particles, some of which have the consistency of silt and some of which have the consistency of sand. Decomposed granite may or may not include organic matter.
As used herein, the term “wax” means any solid (at room temperature), heat-sensitive substance comprised primarily of high molecular weight hydrocarbons or esters of fatty acids that are generally insoluble in water.
The term “emulsified” means to form an emulsion. As used herein, “emulsion” means a fluid formed by the suspension of (1) wax particles in a liquid, particularly water, or (2) liquid wax in another liquid, particularly water.
Several methods and products are known for conditioning or treating soil to create an improved surface. For example, it is known to mix organic binder with soil to create a conditioned soil product. This product forms a relatively hard, durable surface after being wetted, compressed and allowed to dry. Such an organic binder (plantago, also known as psyllium) used as a soil conditioner for stabilizing and enhancing water absorption and retention characteristics of soil is described in U.S. Pat. No. 4,827,665. It is also known to mix inorganic fibers, organic binder and soil to create an improved soil material. Moreover, the present inventor has also employed a mixture of sand, psyllium, and fiber as a loose unbound surface for an equestrian arena with advantageous shock absorbing and cushioning characteristics.
U.S. Pat. No. 5,961,389 to Dickinson discloses an equestrian surface that reduces shock and provides cushioning to the feet of running and jumping horses. The invention generally comprises sand, a hydrocarbon wax and at least one material selected from one or more of the following three classes of ingredients: (1) polyolefin fibers, polyvinyl chloride fibers, wood or a mixture thereof, (2) polyolefin particles; and (3) tire fibers, tire cord or a mixture thereof. Col. 2, 11. 59–64.
It is also, in general, known to add fiber to soil to increase the resistance of the soil to punching shear and reduce the compressibility of soil. Examples are described in U.S. Pat. No. 4,819,933 to V. J. Armond and U.S. Pat. No. 4,867,614 issued to W. W. Freed.
It is also known to use clay as an athletic surface. However, the clay forming such a surface dries out and must be watered to remain plastic and reduce dust. Sand and silt, alone or in combination, are generally too soft for athletic fields. For example, if used on a pitcher's mound, sand and/or silt can be dug out by the action of the pitcher's feet. Organic binders mixed with soil, then watered, compressed and allowed to dry, create a surface that is too hard and brittle for some applications; it is a surface on which a pitcher's cleats may slide.
There remains a need for an improved surface particularly suitable for use in certain (a) athletic applications, such as the non-turf portions of a baseball field, particularly a pitcher's mound, and (b) non-athletic applications.
With respect to a pitcher's mound, as a pitcher throws a pitch his leading foot moves forward and presses down upon the soil on the front portion of the mound. His trailing foot also lands on this front portion of the mound. After throwing a pitch the pitcher returns to the rubber portion of the mound. The impact of the pitcher's feet upon the soil and removal of his cleats can create divots or depressions or otherwise deform the surface of the soil. Often the pitcher and/or the ground crews work to adjust or correct the consistency or level of the surface where the pitcher lands after throwing a pitch. Additionally, the action of player's cleats upon other non-turf portions of infields can create divots or other deformations of the surface that are undesirable.